{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE BangPatterns #-}

import Control.Applicative
import Control.Monad
import Control.Arrow
import Data.List
import Data.Maybe
import Data.Char
import Text.Printf

readInt = ( readLn :: IO Int )
getInts = map ( read :: String -> Int ) . words <$> getLine

which a b f = if f then a else b
mp [ a, b ] = ( a, b )

main = do
	[ w_str, h_str, c ] <- words <$> getLine
	let
		w = read w_str
		h = read h_str
	mapM_ putStrLn $ map ( \i -> take w $ drop ( ( if c == "W" then 0 else 1 ) + ( if i `mod` 2 == 0 then 0 else 1 ) ) $ cycle "WB" ) [ 0 .. h - 1 ]